The basis for many machines is the repetitive generation of reciprocal motion, which motion can then be used to do work. For instance, the reciprocal stroke of an internal combustion motor piston is converted to rotational motion and used to power vehicles, generate electricity and for myriad other uses.
In many instances, reciprocal motion is generated via the introduction of fluid into a cylinder (e.g., as in early steam locomotives) or via the rapid expansion of fluid within the cylinder via combustion or other thermal input (e.g., as in an internal combustion motor). While such mechanisms have proven to be useful and reliable, it would be valuable to develop other mechanisms for generating reciprocal motion.